Recently, the Japanese government revised the three guidelines of its security policy, the National Security Strategy(NSS), the National Defense Program Outline and Midterm Defense Buildup Plan, exceptionally at one time. This means Japan has been seeking the new strategy and strengthening military power considering changing regional security environment. Moreover, Japan revised the security laws for the right to collective self-defense, which authorized the use of force even when Japan is not under attack. Also, Japan renewed the Guidelines for Japan-U.S. Defense Cooperation in twenty years, and has expanded JSDF's scope of activity to a worldwide level. These changes imply Japan would constantly seek to build military forces focusing on naval forces. Because Japan's naval forces, the JMSDF is the means that allow Japan to use its force at anywhere overseas and expand its roles and missions in international society by the basis of the right to collective self-defense. This research will analyze Japan's new maritime strategy and trend of force development and eventually look for the implication on our maritime security These days, Japan has perceived Chinese rapid increase of naval power and pursuing of maritime hegemony as a grave threat. In response to this, Japan is designing new maritime strategy, which are "remote islands defense and recapture" and proactively develop a new type of naval forces to accomplish this new strategy. The Japan's "remote island defense and recapture strategy" is to harden its defensive posture in Nansei islands which correspond to China's 1st island chain for chinese A2/AD strategy and directly encounter with China and to protect its own dominium and maritime interest while supporting US national strategy in East Asia. Japan continues to build compact, multi-functional ship to accomplish "remote island defense and recapture strategy" and keep strengthening its maritime power projection capability to include build of new amphibious ship, and large, multi-functional ship which can provide effective C2. These changes imply that Japan is shifting its strategy from passive and defensive to proactive and aggressive way and continues to pursue naval buildup.The implication of Japan's new maritime strategy and naval buildup needs to be observed carefully and we need to keep developing naval power required to protect our maritime sovereignty and interest.

This paper aims to use crossover analysis to uncover similarities and differences between the U.S-Japan relationship in the World War II era and the modern U.S-China relationship, and to forecast the possibility of the outbreak of war between U.S and China by applying the steps to war theory. The steps to war theory argues that the probability of the outbreak of war between two states within five years would approach 90 percent, if they have ongoing territorial dispute, alliance, rivalry, and arms race. The comparison exposes some similarities with the territorial dispute, alliance, rivalry, but reveals dissimilarities with arms race. U.S-Japan relationship in the World War II era had the arms race, which does not exist the modern U.S-China Relationship. The result of comparison is that the probability for the Outbreak of War between U.S and China correspond to third stage(Risk Level). it means that the probability for the Outbreak of War between U.S and China is 55%. But, There are four elements(① Perception of Leader ② Mutual dependence of economy ③ Possession of nuclear weapon ④ Ravages of war) that reduce the probability for the Outbreak of War. Considering the four elements, the probability for the Outbreak of War between U.S and China is a slim chance. But the probability for the Outbreak of War between U.S and China is excluded because of territorial dispute, alliance, rivalry. So, This paper suggests three points.(① Developing military options ② Reducing the misconception of intend, ③ Promoting navy exchanges) to prevent of Outbreak of War.

The purpose of this article is to analyze the progress of North Korea's SLBM threat, and to assess the technological capacity and threat level of its SLBMs. Currently, North Korea has approximately 1000 ballistic missiles, such as the SCUD, Musudan, and Nodong, in stock. This article pays close attention to the background and strategical implication behind North Korea's obsession with developing SLBMs despite possessing sufficient means to launch provocations with its current arsenal of ground based ballistic missiles and conventional weapons. Based on the abovementioned analysis, this article will recommend possible response directions for the ROK Armed Forces to North Korea's SLBM threat. It is highly difficult to detect SLBMs due to its stealthy nature, as it is launched underwater after covert infiltration. North Korea's SLBM is considered a game changer in that even one SLBM can significantly change the strategic balance of North East Asia. North Korea's SLBM test launch in August has made a 500km flight, landing 80km inside the JADIZ (Japan Air Defense Identification Zone), and as such, it is assessed that North Korea already possesses underwater ejection and cold launch capabilities. The most realistic response to North Korea's imminent SLBM threat is bolstering anti-submarine capabilities. ROK Armed Forces need to upgrade its underwater kill-chain by modernizing and introducing new airborne anti-submarine assets and nuclear-powered submarines, among many options. Moreover, we should integrate SM-3 missiles with the Aegis Combat system that possess strong detection capabilities and flexibility, thereby establishing a sea-based Ballistic Missle Defense (BMD) system centered around the Aegis Combat System, as sea-based ballistic missile threats are best countered out in the seas. Finally, the capabilities gap that could arise as a result of budgetary concerns and timing of fielding new assets should be filled by establishing firm ROK-US-Japan combined defense posture.

The security environment surrounding the East Asian seas is rapidly changing due to the naval arms race among coastal states. The arms race is likely to worsen the security dilemma of the countries involved, thus increasing the chances for armed conflicts. It is too early to tell how the contemporary naval arms race in the region will evolve. But, for sure, the level of uncertainty is increasingly becoming high and intense. At the same time, there is emerging a legal warfare or lawfare among the rival countries. In particular, the United States and China have been involved in a serious debate about the nature and scope of the right of innocent passage and freedom of navigation in other countries' maritime zones. In collaboration with its regional allies, the United States has also put normative pressures on China with its excessive claims in the South China Sea. The latest arbitral tribunal case between the Philippines and China illustrates the point. With both arms race and normative competition in play, the future of East Asian maritime security will remain very complex and uncertain.

On 12 July 2016, China's maritime claim to most of the South China Sea (SCS) based on the so-called nine-dash line was rejected by the Arbitral Tribunal, constituted under Annex VII to the UN Convention on the Law of the Sea (UNCLOS) concerning issues in the South China Sea including the legality of the so-called "nine-dashed line", the status of certain maritime features and their corresponding maritime entitlements, together with the lawfulness of certain actions by China which the Philppines, in a case brought in 2013, alleged were violations. As having the Tribunal determined that China's claim had no legal grounds in UNCLOS, thus undermining China's claims, and establishing that China has no exclusive legal rights to control the area roughly the size of India. There are some major implications from the Tribunal's ruling in the Arbitration award. These include implications on: how to delimit the maritime boundary in disputed waters, how to promote maritime confidence-building measures, how to safeguard maritime safety and security, and how to promote the rule of law in the SCS. Since its application of UNCLOS in East Asia, it has been obvious that the only way to resolve maritime disputes in the region is to build strong maritime cooperative partnerships under the auspices of the rule of law.

A unanimous Award has been issued on 12 July 2016 by the Arbitral Tribunal constituted under Annex VII to the United Nations Convention on the Law of the Sea in the arbitration instituted by the Republic of the Philippines against the People's Republic of China. The current security issues in the regional sea shall be carefully reflected to anticipate whether the Award could resolve the existing political conflict or rather will grow military tension in the region. The Award clearly directs the scope of delimiting maritime jurisdiction to coastal States in the Southern China sea, so it seems to help facilitating finding resolutions of regional disputes on maritime boundaries. On the other hand, there are several limitations in reality to implementation of the decisions included in the Award. USA could use the decisions to restrict military activities and exercise of unilateral maritime jurisdiction by China in the region, while China shall encounter guilt to illegitimacy of its activities as well as shaking the legal foundation of its policy in the region. Then the resolution of this dispute through application of international law would rather cause more political confusion. The intension of bringing the case to an international court were to resolve political difficulties. If, however, the political difficulties are not properly reflected in the legal decisions, such decision would possibly raise more political risks.

This research deals with the PLAN's capabilities and its implication for regional security, and suggests some measures for maritime security cooperation among regional states. China has began to focus its national strategy more on 'rising as a new maritime power' since the 18th Party Convention in November 2012. Chinese new strategy aims at building a strong navy, contributing economic prosperity and national security, and thus elevating its prestige in international society. Most of all, building a strong navy is the foremost task at this time, and that is why the PLAN has the priority for military modernization. Chinese new maritime strategy could cause naval arms race in East Asia and aggravate maritime territorial disputes among concerned parties. It is the time for regional states to discuss some measures to build confidence, such as arms control of naval weapons, establishment of multilateral maritime security mechanism, and foundation of regional security regime, thus enhancing regional maritime cooperation.

As North Korea's asymmetric threats are growing, there have been numerous discussions to find out effective counter-measures and many official plans and procurements efforts have been established. However, discussions on ROK Navy's roles in countering North Korea's asymmetric threats have been taken place very limitedly. Decision makers and military planners put enormous efforts in getting counter-measures, however, most of the options on the table are systems of Army and Air Force. This is true if one looks at components of Kill-Chain, KAMD, and KMPR. With worsening security environment of the Korean peninsula, it has been said by many commentators that ROK Navy needs to consider expanding its roles in countering against North Korea's asymmetric military threats. They asked ROK Navy to go beyond the mind-set that has confined Navy's roles in deterring North Korean naval threats. That is, ROK Navy should fight 'from the sea' as well as fight 'on the sea.' If ROK Navy begins to think about fight 'from the sea,' there would be many possibilities for the Navy to be a part of countering North Korea's asymmetric military threats. In order to pursue proactive roles in countering North Korea's asymmetric threat, ROK Navy needs to consider various options. Massive missile forces, nuclear-propelled submarines, naval special forces may be some of them. With those measures, ROK Navy would launch massive and decisive attacks from the sea without risking survivability of our forces. Considering North Korean Navy's weakness, it is very probable that sea would be safer place than ground or sky. Expanding ROK Navy's roles and being a proactive deterrent forces against North Korean asymmetric threats would provide very reliable counter-measures to South Korean military. Thus, military planners should think how to take the best advantage of expanded ROK Navy's roles and capabilities against North Korean asymmetric threats.

본 논문은 자위권 사용과 군사력 사용 간의 관계를 분석하고 이를 한반도 서해에서의 한국과 북한 간 해상긴장 상황에 적용시킨 이슈를 다룬다. 국가가 행사하는 자위권(self-defense: 自衛權)은 기본적으로 전쟁 방지를 위한 기본적 원칙이다. 그러나 이는 군사력 사용(Use of Forces: 軍事力 使用) 또는 무력행사(武力行事)이라는 측면에서 칼의 양날과 같은 결과를 낳는다. 즉 자위권 행사로 전쟁의 확산을 방지하는 반면에 자위권 행사로 상대방에 대한 적성(敵性)을 인정해 주는 경우이다. 반면 북한의 군사도발은 전방향적이며, 1953년 한반도 정전협정 위반이다. 1953년 정전협정 체결 이후 양국은 서해 북방한계선(NLL)에서의 군사적 충돌을 거쳤으며, 이는 과연 한국이 자위권 차원에서의 방어태세와 군사력 사용 측면에서의 대응태세 간에 괴리가 존재하고 있다는 것으로 나타나고 있다. 당연히 피해를 받는 곳은 한국이며, 이는 서해 북방한계선에서의 남북한 해군 간 대결국면에서 나타나고 있다. 이에 본 논문은 자위권을 국가 차원 행사하는 수준과 작전에 투입된 현장 작전 지휘관 차원에서 행사하는 수준으로 구분하여 다룬다. 서해 북방한계선 부근 수역에서의 북한의 해상 군사도발에 대해 현장 작전 지휘관이 행사하는 자위권은 대한민국 정부 차원에서의 자위권 행사와는 다르면, 이 문제를 국제법을 중심으로 분석하기에는 너무나 많은 제한점이 있다. 현행 국제법상 국가 자위권 문제는 군사력을 동반하는 문제로서 그 행사요건이 매우 애매모호하고 까다롭다. 그러나 현장 작전지휘관의 자위권 행사는 단호해야 하며, 이는 군사력 운용으로 나타나야 한다. 실제 서해에서의 남북한 대결국면에서의 대한민국 해군의 자위권 행사는 정전협정에 의거 제한되고 있으며, 이는 2010년 북한의 천안함 침몰과 연평도 폭격도발 시 대한 민국 해군과 해병대의 대응에서 증명되었다. 현재 대한민국 국방부는 현장 작전 지휘관에서 소위 '선제적 자위권 행사' 부여 필요성에 대한 논의를 진행 중으로 알려져 있다. 이에 따라 선제적 자위권 행사를 위한 조치들을 제도화하는 움직임을 보이고 있다. 예를 들면 2013년 발표된 대한민국 합참과 유엔사령부/한미 연합사령부/주한미군사령부 북한 군사 도발에 대한 대응계획(ROK JCS and UNC/CFC/USFK Counter-Provocation Plan)이 이를 간접적으로 증명하고 있다. 선제적 자위권은 행사에 있어 몇 가지 원칙을 요구하고 있으며, 이에 대한 합법성 문제는 아직 해결되고 있지 않다. 따라서 이 문제와 북한 군사도발 시에 대한 대한민국의 선제적 자위권 행사 간 연관성 문제를 어떻게 해석할 수 있는가에 대한 연구가 필요한 실정이다. 평시 군사력 사용에 따른 무력행사의 적법성은 그 인정이 대단히 어려운 것이 현실이며, 이에 따라 북한의 군사도발에 대한 가장 효율적 방안이 선제적 자위권이라면, 이에 대한 법적 대응이 무엇인가에 대한 제도적 근거를 필요로 할 것이다.

최근 남중국해(South China Sea: 南中國海)가 동아시아 해양안보의 중심 이슈로 대두되고 있다. 아울러 남중국해 문제가 당사국 간 해양분쟁 및 해양경계획정 이슈만이 아닌, 제3자 개입 등의 다자간 해양분쟁과 대립으로 확산되는 매우 복잡한 양상을 보이고 있다. 이러한 남중국해 해양문제는 미국과 중국 간의 강대국 경쟁구도가 적용되어 힘의 시현을 위한 대결 국면이 되는 반면, 중국이 전통적 해양이익을 구단선(nine dash line)을 근거로 주장하면서 국제법 적용 문제에 따른 법적 문제의 성격을 나타내고 있다. 이에 따라 최근 남중국해 상황은 '항해의 자유(Freedom of Navigation)' 보장을 주장하는 미국, 역사적 권리 보장을 위해 일반적 조치를 강행하고 해군력을 증강시키는 중국, 그리고 남중국해를 경유하는 수많은 선박들의 항해 안전(navigational safety)을 강조하는 역내 국가 간 의견이 표출되는 복잡한 양상으로 나타나고 있다. 특히 최근 중국이 상설중재재판소의 남중국해 중재판결을 무시하여 국제법 적용이 어려운 가운데 포괄적 동아시아 해양안보 차원에서 남중국해 이슈 해결을 위한 새로운 접근방안이 요구되고 있다. 이는 남중국해에 대한 당사국 간 평화적 분쟁 해결과 더불어, 강대국 간의 전략적 함의에 의한 해결이 병행되어야 함을 의미한다.